1. Field of the Invention
The present invention relates to a mechanism for rotatably supporting a rotary member of a keyboard such as, for instance, of an electronic piano or the like.
2. Description of Related Art
As a mechanism for rotatably supporting a key of an electronic musical instrument, there has hitherto been known, as shown in FIG. 18, one which is made up of a bearing member d and a key f. The bearing member d has a pair of wall plates "a", "a". Each of the wall plates has formed therein a hole b which laterally (i.e., perpendicularly to the longitudinal direction of the key) penetrates the wall plate "a", and a guide groove c which is formed in the wall plate "a" so as to be in communication with the hole b and also have an access from above. The key f is provided at one longitudinal end thereof with laterally extending rotary (or pivot) shafts e, e of oval cross section, one on each side wall thereof. The rotary shafts e, e of the key f are thus fitted into the holes b, b through the guide grooves c, c.
In the above-described conventional mechanism for rotatably supporting the key, the rotary shaft f of the key f has an oval cross section. Therefore, there is a disadvantage in that sufficient surfaces of contact between the rotary shafts e, e and the bearing members d, d cannot be obtained, with the result that the mechanical strength of the rotary shaft is low.
In view of the above-described disadvantage of the conventional art, the present invention has an object of providing a mechanism for rotatably supporting a rotary member of a keyboard, such as, of an electronic piano, or the like, in which the mechanical strength of a rotary shaft of a key, or the like, does not decrease.